The effect of electrode potential

Analytical models of modified electrodes for NADH oxidation 

Best-fit parameters from the analysis of the data in Fig. 2.23 for the currents for NADH oxidation in the absence of added NAD+ at poly(aniline)/poly(vinylsulfonate)-modified electrodes, in each case, the data were fitted to equation (2.20) for the I/II boundary (n is the number of data points used) 

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Otherwise, the effect of electrode potential and kinetic parameters as contained in the relevant expression for the PMC signal (21), which controls the lifetime of PMC transients (40), may lead to an erroneous interpretation of kinetic mechanisms. The fact that lifetime measurements of PMC transients largely match the pattern of PMC-potential curves, showing peaks in accumulation and depletion of the semiconductor electrode and a minimum at the flatband potential [Figs. 13, 16-18, 34, and 36(b)], demonstrates that kinetic constants are accessible via PMC transient measurements, as indicated by the simplified relation (40) derived for the depletion layer of an n-type electrode. 

It has been known that adsorption kinetics and/or thermodynamics of proteins depend on the electric or electrochemical properties of solid supports on which the proteins are adsorbed. This has led us to elucidate the effects of electrode potential on the adsorption behavior of avidin on the electrode surface. For this purpose, the electrode potential of a Pt electrode was varied systematically in the range of -0.5-+2.0 V in an avidin solution (pH 7.4). Although the data was somewhat scattered, a general trend was observed that the adsorption of avidin is suppressed by the application of a positive potential (+1.0-+2.0 V). This may be originating from the fact that avidin is a basic protein and has net positive charges in the solution of neutral pH. In the potential range tested, no significant acceleration in the adsorption was induced. 

One of the most important features of HPLC/EC is the effect of electrode potential on detector response. Figure 3 illustrates this feature wherein the response of the detector as a... 

How is the effect of electrode potential to be introduced into the potential energy diagrams This can be done by realizing that in the reaction... 

In particular, Yeager and co-workers (42) have described a = a 4- j3 T for the reduction of oxygen on platinum in concentrated phosphoric acid in the temperature range 25—250°C with cathodic Tafel slopes nearly independent of temperature (a — 0.08 and j3 = 0.0012/K). The effect of electrode potential on the reaction kinetics is mainly through the entropy of activation [43]. 

Br0nsted factor for the effect of electrode potential on the Fermi level of electrons, causing change of AG with V (see p. 6). 

A formally more explicit representation of the effect of electrode potential and associated role of temperature on electrochemical reaction rates follows from the transition-state theory applied by Glasstone et al soon after the appearance of Butler s paper. The rate constant of a chemical process is written as... 

Fig. 2 Schematic representation of the effect of electrode potential on the free energy versus reaction coordinate curves for an electron reactant at two electrode potentials E = Eg (solid line) and E < Eg (broken line).

Young, L. M., et al., "The Effects of Electrode Potential and Temper on Environment Assisted Cracking in AA 7050, Light Weight Alloys for Aerospace Applications IV, The Minerals, Metals and Materials Society, 1997, pp. 3-18. 

FiG. 13—The effect of electrode potential on relative CF crack propagation rate in the C-Mn steei/chlorkle system, as portrayed by the crack tip hydrogen production current calcu-iated from a crack chemistry model. The equation of the fine from regression anafysis is y = 2.39 + 0.22 x, where y is the normafized (dimensionless) crack growth rate and x is crack tip hydrogen production rate in Alcaf [7. ... 

Before discussing the effect of electrode potential on reaction rate in Chapter 3, we will look briefly at the structure of the region adjacent to the electrode surface. We will consider only the elementary reaction ... 

State the effect of electrode potential on corrosion fatigue crack growth. 

To further analyze the data, the Afi method was considered to determine where the Ox species resides in the TNC active site. The difference spectra for the XANES (Figure 15.7) are presented in Figure 15.8 using the indicated XANES scans as the reference scan. Note that different reference scans arc used to amplify either the effect of electrode potential (same gas), effect of O2 presence (same potential E), or both (combination of gas and potential). For example, the situation where only the effect of electrode potential is considered was calculated using Equation 15.5 ... 

As seen from this review of the published data, stereospecificity in electrode reactions is still a little-investigated subject. In some cases the effect of purely electrochemical factors can be clearly traced, in other cases a much greater part is evidently played by factors which also arise in normal homogeneous reactions. Detailed investigation of the effect of electrode potential on the stereochemistry of oxidation and reduction products is of undoubted interest and may lead to methods for controlling the course of many of these reactions. 

SERS are given in Section 6 in Section 7, the effect of electrode potential on SERS is considered and in Section 8, chemical systems which have been investigated with SERS are discussed. 

Previous considerations in Section 7.1 of the effect of electrode potential on SERS intensities have dealt with the situation where an electrode reaction... 

By considering the kinetic substantiation of the Nernst equation, Audubert[2] and Butler[3] were the first to formulate the semiquantitative concepts concerning the effect of electrode potential on the rate of an electrochemical process. In its present form, the concept of slow discharge was put forward by Erdey-Gruz and Volmer[4]. Their approach was based on a consideration of the effect of potential on the activation energy of an electrode process and led to the introduction of a measure of this effect, viz. the transfer coefficient a. 

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